With Mark IV ABS System

Pump Inlet Hose
The hose from the reservoir to the pump is connected to the pump- by means of a plastic elbow.

Electric Motor
The electric motor which drives the pump is a D.C. motor with a built in speed sensor so the the Electronic Control Unit (ECU) can receive information to the effect that the pump motor is running

The motor can be replaced only as a complete unit with the pump and valve block.

Hydraulic Pump
The pump unit delivers the necessary extra volume of fluid under Antilock Brake System (ABS) control to the brake circuits.

The pressure on the additional brake fluid flow is determined by the brake pressure in the master cylinder, which in turn is proportional to the pedal force applied.

The pressure during normal braking modulation is around 80 to 100 bar. The pressure almost never exceeds 100 bar. The electric motor and pump have capacity to spare so that they can always produce sufficient volume and pressure in all braking situations

The hydraulic pump can be replaced only as a complete unit with the pump and valve block.